Saint Etienne handed a 2-0 defeat to Reims in a Saturday's French Ligue 1 fixture, and Wahbi Khazri was a decisive figure in the encounter.
The hosts seem to continue from where they stopped in their seven-goal thriller win over Angers SCO last week.
With both sides yet to settle into the tie at the Stade Geoffroy-Guichard, Mathieu Debuchy grabbed the curtain raiser in the first minute with Khazri providing the goal.
In the 39th minute, the Tunisia World Cup added the second off an Ole Selnaes assist. The goal was the former Sunderland winger's sixth in 12 league appearances this season.